Albinism in IN BIRDS Albinism: mutant of loci (position of a on a chromo ome) involved in Jim McCormac production contribute to this condition. Manifested by lo s of melanin not ODNR Division of Natural Areas and Preserves only from , but also from soft tissue such as , . and 1889 Fountain Square Court, Columbus, OH 43224 : mutant of loci that control melanocytic life functions­ [email protected] particularly the migration of melanoblasts ( precursors} from the neural ere t in the embryo---contribute to this condition. Jt results in a reduction or ab­ With the exception of guUs (most of which are various shades of gray above), sence-either localized, or rarely throughout the -of melanin. Partial we see very few species of predominantly white birds in Ohio. White birds tend to leucism is fairly common. resulting in the "pied'' birds; e.g., a with a white head cau e immediate excitement-after all, they may tum out to be goodies like Ro s's but otherwi e normal plumage. goose. snowy owl, or white ibis. Only about 13 species of Ohio birds-out of 410- Disadvantages of Albinism/Leucism are mostly white at least in some plumage, and many are rare to uncommon vi itors. l consider 13 pecies of birds that regularly visit Ohio as primarily white in their Every now and then, however. a white bird shows up that later proves to be an natural state. There a few others. such as wood 1ork. ivory gull. and white ibis. but albinistic individual of a common species. These can be real puzzlers. Without the the e are accidental in occurrence and not included here. They are American white familiar colorations on which we are used to basing our identifications. the identity pelican, great egret, snowy egrel egret, snow goose. Ros 's goose. mute wan. of even common birds can generate lots of debate. Witness the recent discus ion of tundra swan, (introduced). glaucous gull. Iceland gull. snowy owl. photos ( 16-20 December 2001) po led to the ID-Frontiers internet list of a sparrow­ and snow bunting. like bird in Texas. At a glance, it looked very redpoll-like, but ultimately the When looking at this group of only about 3% of our avifauna, two trends con ensus among experts was that it was an albinistic chipping sparrow. become apparent. First, mo t of these species are relatively predator-free, large What is Albinism? enough or clo e enough to the top of the food chain that predation is generally not a Es entially. albini mis a genetic disorder that inhibits the formation of tyro i­ problem. The others tend to flock. finding safety in number rather than protective nase. an that causes the ynthesis of melanin. a dark . There are four coloration. Thus, the disadvantages of being white and sticking out like a sore thumb degrees of albinism, as defined by geneticists Hun and Mueller in 1941: I) total are offset by behavioral or rnorphologica1 characteristics. albinism. the rarest form, in which the individual is all white with eyes: 2) Generally speaking, there are probably no benefits for a bird in being albinistic incomplete albinism. in which melanin (in birds) is completely ab ent from eyes. or leucistic, and it's likely thi genetic anomaly isn't selected for perpetuation. Most kin, or feathers. but not all three: 3) imperfect albinism, where melanin is only trongly albini tic birds have a short shelf life as compared to other normally partially inhibited, creating a pale (a well-known example are the ''white·· plumaged individuals of the same species. They stand out co predators, and many used by the entertainers Sigfried and Roy); 4) partial albinism, the most albinistic passerines, for example. are likely picked off by accipiters in short order. common form, where localized body parts ate white or whitish. The majority of As with . aJbinistic birds tend to have weak eyesight, and while people with unnaturally white birds are in this fourth category. thi condition often have brittle bones, birds have weaker quills. In addition, Albinism is a recessive genetic characteristic, and generally quite rare in an) there are numerous accounts of albinistic individuals being hunned by others of population. In humans. it manifests itself in about one person out of every their kind. which is nature's indifferent way of reducing the likelihood that they wiJJ 20.000. Perhaps the best-known people with this condition are the rock musicians breed and perpetuate this trait. Johnny and Edgar Winter. According to the Hardy-Weinberg Equilibrium (a formula for determining population genetics), about one sperm or egg in 141 carries Examples of Albinism in Birds the recessive gene for albinism. This translates to a likelihood of 1.4% that an The incidence of albinism is just an odds game-the bigger the popuJation, the individual will become a carrier for albinism. Albinism is probably about equally more likely thi condition will be ob erved. Unsurprisingly then. the number one rare in birds. It's been estimated that only 0.5% to l.0% of all birds display any sign pecies displaying albinism in North American birds is the , followed of albinism-partiaJ or complete. by the house sparrow. In theory, however, any species may display albini m or leucism. and this can lead to some real puzzlers in identification. Oftentimes one AJbinism vs. Leucism does not have long to observe these birds. becau e of the aforementioned predation The difference between albinism and leuci mis quite technical and, practically factor. but when a larger. relatively predator-free albinistic bird appears, ic may be peaking, probably not that important to bird ob ervers. Either condition causes a seen for years. This is the case with the that has frequented the area of whitening of the plumage. Bul for technophile , here's the basic difference: Egypt Valley in Belmom County, Ohio for at least four years. While not a complete

36 The Ohio Cardinal Vol. 25. No. l • Autumn 2001 37 McCORMAC ALBINISM IN BIRDS albino, the bird displays extensive white in the body and wings. and is a very triking white. In this case, the plumage i so altered from the typical that coloration i no real ight. help in making the identification. l was given ome details of its habits from ob ervers Sometimes. though, it is very difficult to determine the species of an unnaturally that assisted in the process of elimination. The bird hopped-rather than walked­ white bird. Imagine the surpris~then frustration-experienced by the owners of a and spent most of its time foraging on the ground. When startled, it would fly into South Carolina feeder when an es entially aJl-white made an appear­ bushes or trees. Unfonunately, no vocalizations were heard. ance. This bird, seen in 1999, was established as a ruby-throated hummingbird only Because the bird was reported to hop rather than walk, snow bunting can be when captured and closely studied. As would be expected, it was initially reported as ruled out. It also displayed a kulking behavior, sticking clo e to cover and eeming an albino, but actually proved to be leucistic, as its feet, bill, and legs were normally to flatten to the ground periodically. This is very characteristic of sparrows in the pigmented. genu Spize/la, which tend to be shy and retiring. While somewhat more ubjective. In September 200 I, a finch-like bird appeared in rural Licking County. Ohio, the relatively slender body. longish tail, and largish bill are also indicative of that was trikingly patterned in white and dark . Understandably, it was at first Spi:ella. Although bard to definitively ascertain from the photos, the biU al o called a snow bunting. It was quickly realized that it was something else, though, as appears to be pinkish. its behavior, size and hape, and coloration were not right for that specie . Figuring AU in all, the overall shape, biU, and habits are consistent with one of our native out its true identity was very difficult, as is often the case with aberrant bird , and parrows, in particular the field sparrow Spi:ella pusil/a, and that is my gue . If that ultimately it could only be guessed at. While I have seen only pictures-and not i correct, this bird definitely falls into the realm of odditie . as I can find only one great ones-I believe a good hypothesis can be made as to its identity. reference for an albinistic field parrow: a bird documented in South Dakota in the early 1980s. Identifying AJbinos Albinistic or leucistic birds, in addition to providing an unusual spectacle, offer When working with an albini ticneucistic bird, who e natural markings are an excellent chance to bone one's observational kills and powers of deduction. mo tly obliterated by white. there is a suite of factors to consider in drawing conclu­ They al o erve as a good reminder that first impre sions aren't always correct, and sions about its identity. One, closely examine the plumage. Oftentimes in a leucistic aberrant individuals must always be considered as a possibility-not just rarities . ~ bird, the typical marking will bleed through the whitish overlay, although they may not be evident until the bird can be een well. White feathering may not mask some markings. Two, examine its habits: is it feeding on the ground or in trees, hopping or walking, have an undulating or straight flight, etc.? Three, pay attention to structure, such as overall ize, shape, length of tail. legs, and wing , type of bill, etc. Albini mneucism will not affect these characteristics. Four, what are its as ociates? Sometime , in flocking birds, the company "whitey" keeps will be a dead giveaway. And last, Ii ten for vocalizations. They ~~~ii~ could clinch the identification. With careful study, many albinis­ tic birds are not too tough to figure out. The Licking County sparrow was. however. As can be seen from the photo , thi bird is mostly white, with This alb1nist1c sparrow appeared in Licking what appear to be blackish primaries County in September 2001. Its identity is and markings on the back. Any still unknown. but field sparrow seems to normally pigmented feathering will be the best guess. Photo by Mike Flynn appear darker when set off against

38 The Ohio Cardinal Vol. 25, No. 1 • Autumn 2001 39